import React, { Component } from 'react'
import {withRouter} from 'react-router-dom';

class Header extends Component {
    back = () => {
        this.props.history.goBack();
    }

    forward = () => {
        this.props.history.goForward();
    }

    go = () => {
        this.props.history.go(2);  
    }

    render() {
        // console.log("Header组件收到的props是：" ,this.props);
        return (
            <div>
                <div className="page-header">
                    <h2>React Router Demo</h2>
                    <button className="btn btn-default" onClick={()=>{this.back()}}>后退</button>&nbsp;
                    <button className="btn btn-default" onClick={()=>{this.forward()}}>前进</button>&nbsp;
                    <button className="btn btn-default" onClick={()=>{this.go()}}>go</button>
                </div>
            </div>
        )
    }
}

export default withRouter(Header)

//withRouter可以加工一般组件，让一般组件具备路由组件所特有的API
//withRouter的返回值是一个新组件

